1. Field of the Invention.
The present invention relates to the field of fluid control systems such as sprinkler systems for watering and irrigation purposes and valves for use in toilets and the like.
2. Prior Art.
Fluid control systems are widely used for a variety of purposes. Some of these systems simply comprise a set of valves which are manually opened and manually closed. Other systems comprise one or more valves which are manually opened and automatically closed a short time thereafter, such as in toilets, and still others comprise a complete system for periodically opening one or more valves for a predetermined length of time, such as are used in automatic lawn watering systems. Inasmuch as the preferred embodiments of the present invention disclosed herein are specifically adapted for use in fully automatic watering systems and in toilets, the prior art in these two types of water control systems will be discussed, it being recognized and obvious from the disclosure herein that the present invention is in no way limited, only to these two applications.
Automatic sprinkler systems for automatically watering lawns, fields and the like are well-known in the prior art. These systems are generally adapted to open one or more valves at predetermined intervals for predetermined durations, as controlled by one or more clocks, so as to direct water to the various sprinklers as desired.
The most common of the prior art systems are designed to operate on a standard 115 volt 60 cycle power source. A central clock is used for timing to control the distribution of power to the various solenoid valves for opening the valves in the various water lines. Typically, the solenoid valves are designed for automatic closing, and to be opened and to remain open only during the duration of a low voltage power supply thereto. For such purposes, the 115 volt 60 cycle power is transformed through a step-down transformer to a lower voltage so as to be more readily and safely dispatched to the various solenoid valves through underground conduits.
The above described systems are by far the most common systems in use, particularly in residential installations. However, these systems have a number of problems associated therewith which prevent their more widespread use. Though such systems are expensive, their cost is generally not considered prohibitive. However, the purchase of a system is but one part of the expense associated with the use of the system. The installation, say in a residence, requires wiring the system into the house power lines and running underground wires from the central clock to each of the solenoid valves, as well as placement of the solenoid valves in the respective water lines. In new housing developments, the cost of installing such a system before driveways, patios and the like are put in may well be more than the purchase price of the system, and in older residences may be prohibitive because of the presence of patios, driveways, swimming pools and the like, and further, the reluctance of the homeowner to have his landscaping disturbed. Consequently, while such systems meet the basic objective of periodically watering an area, the total cost associated with such systems and the inconvenience and difficulty of installing such systems has prevented the more widespread use thereof.
Battery-operated sprinkler systems are also known in the prior art. By way of example, a battery-operated system is disclosed in U.S. Pat. No. 3,547,154 entitled "Irrigation Timing Control Apparatus." That system uses a battery to operate a motor driven timer which periodically rotates a permanent magnet on a timer disc into proximity with a magnetically actuated reed switch which turns on a solenoid valve and a time-delay network, which in turn, turns off the solenoid valve after the desired time. The solenoid valve used with this system is of a magnetically latching type, turning on with a pulse in the first direction and turning off with the pulse in the second direction. However, in the system described in that patent, no means of reversing the direction of the current pulse of the solenoid coil is disclosed, but instead a center tapped coil is used, with the on pulse being applied to one end of the coil with respect to the center tap, and the off pulse being applied to the other end of the coil with respect to the center tap. Consequently, only one-half of the solenoid coil is usable for either turning on or turning off the valve, thereby detracting from the efficiency and force, or adding to the cost and size of the device.
In the above described battery-operated system, no means is disclosed whereby a single clock may be used to sequentially operate the series of slave valves. Upon closure of the reed switch, a capacitor starts to charge, and upon reaching a particular voltage, is discharged through one-half of the solenoid coil to turn on the valve. Consequently, the reed switch must remain closed for a sufficient length of time for the capacitor to be charged through various current limiting resistors. Thus, the system is not responsive to a pulse control signal, and a turn off signal somehow derived from one unit would in no way be operative to turn on the next unit. Thus, in the system disclosed, each valve has associated therewith a timer and full circuitry for operation of the system. The timer itself is a motor actuated device, thereby being relatively expensive, having a limited life and requiring a very significant, continuous power for proper operation.
Also known in the prior art are moisture sensors for use in sprinkling systems to control the application of water based on the particular needs of the soil. Some of these moisture sensors are designed as probes to be inserted in the soil and electrically connected to the sprinkler system so as to sense the moisture content in the soil. Such moisture sensors are disclosed in U.S. Pat. No. 3,113,724, entitled "Automatic Watering Systems" and U.S. Pat. No. 2,578,981, entitled "Electronically Operated Soil Sprinkling or Irrigating Systems". Such systems are useful to prevent the operation of the sprinkler system when the ground already contains adequate moisture because of rain or high humidity occurring or prevailing since the last sprinkling. However, sensors placed in the ground must be placed at a position which is representative of the total area being watered and must be wired into the sprinkler system. The sensor and the wires connecting it to the sprinkler system are generally easily damaged by lawn mowers and the like, and since the sensor is adapted to measure the conductivity of the soil, and particularly to sense the high conductivity of the soil for moisture, a broken lead to the sensor will provide a signal equivalent to dry soil, thereby allowing operation of the system when the soil already contains adequate moisture.
Another type of moisture sensor is shown in U.S. Pat. No. 3,339,842 entitled "Systems for Water Control". This type of sensor is conected into the water line downstream of the solenoid valve so as to collect a portion of the delivered water in an open container while the valve is open. The apparatus is arranged so that a subsequent opening of the solenoid valve will be prevented until at least a predetermined amount of water in the container has evaporated. Thus, rainy weather and/or humid weather will reduce the frequency of operation of the system as desired. However, the apparatus disclosed therein is separate and apart from the solenoid valve and is adapted to operate in conjunction with motors, relays and the like and therefore, is not suitable for battery operation because of the relative amount of power required.
The prior art systems are generally comprised of an assembly of old and standard components to achieve the desired purpose. By way of example, none of the prior art systems have anti-syphon valves incorporated as part of the solenoid valve, or integral with any other component of the system, though such valves are commonly required as part of such systems in many instances. Furthermore, prior art anti-syphon valves, as a separate component, have the anti-syphon valve element directly in the flow stream movable from a position blocking the reverse water flow and venting the sprinkler system to the air, to a position of allowing forward water flow and sealing the air vent. These valves perform the function of preventing substantial back-flow of water from the sprinkler system back into the public water system upon loss of pressure in the public water system by obstructing the water line against reverse flow and venting the sprinkler side of the line to remove the water from that point. To accomplish this, the anti-syphon valves are deliberately placed at a level substantially higher than the highest sprinkler head so that the venting of the system at that point will prevent syphoning of the system into the public water supply. However, it has been found recently that micro organisms, once entering a water line, are able to pass through a closed valve which contains water on both sides of the valve. Consequently, to prevent this, one side of the valve, namely the low-pressure side, should be vented to the air so that the various surfaces may quickly dry and thereafter not present a water pool for collection and multiplication of such micro organisms. Prior art anti-syphon valves do not achieve this latter purpose, inasmuch as the anti-syphon portion is somewhat removed from the on-off valve. When the on-off valve is turned off, the water flow stops and the anti-syphon valve element effectively sinks in the water in the anti-syphon valve to a closed-position so as to prevent substantial backflow. Since the anti-syphon valve element closes merely by the force of gravity, and in general is closing on a less than perfect valve seat, the anti-syphon valve closing may be better described as presenting an obstruction to back-flow as opposed to a seal against backflow. Consequently, micro organisms may freely collect and multiply in the water between the anti-syphon valve and the on-off valve, and will be invited to collect in this region by the water trapped above the anti-syphon valve element and the freedom with which such organisms may travle therefrom through the anti-syphon valve. Thus, it may be seen that though prior art anti-syphon valves prevent gross reverse flows from loss of water pressure in the public water supply, such valves do not prevent the accumulation and distribution of micro organisms in the water system in every day use.
It may thus be seen that prior art battery-operated sprinkler systems are complex systems having a short battery life or requiring very large batteries, and require an individual timer for each valve in the system. Such systems do not incorporate moisture-sensing devices and are not capable of sequential operation from a single clock located at one of the valves. Anti-syphon vlaves used with such systems are separate valves having a considerable expense associated therewith and not being adapted to prevent the flow of micro organisms into the public water supply. There is, therefore, a need for a simple, reliable and inexpensive battery-operated sprinkler system which may be readily installed within a new or existing sprinkler system without substantial wiring, and which may give sequential operation of a plurality of sprinkler valves from a single clock disposed in one of the vlave units.
Prior art toilets generally fall within two categories, these two categories being toilets for residential use and toilets for use in public or semi-public buildings, with this latter category being further subdividable into toilets where the flushing is manually initiated and toilets which are automatically periodically flushed.
In toilets intended for residential use, a typical installation will comprise a porcelain receptable connected to a drain and partially filled with water, with a seat assembly disposed thereabove and a water reservoir or tank generally adapted for mounting to a wall immediately behind the porcelain receptacle so as to be operable to discharge water contained therein into the receptacle. A float assembly and float actuated valve is located in the tank so as to control the water level in the tank and to refill the tank after it has been discharged into the receptacle. A second float is disposed over a discharge opening in the bottom of the tank so that once it is displaced therefrom, it will float away from the discharge opening until the tank is substantially emptied of water. In this assembly, the purpose of the tank is twofold. First, it provides a reservoir for a predetermined amount of water and may provide an instantaneous water flow rate unobtainable through the water supply line connected to the toilet. Secondly, it functions, at least indirectly, as a time delay mechanism for turning off the water supply line when a predetermined amount of water has been allowed to flow into the tank. However, it has been found that water flow rates obtainable directly from the water supply lines in an ordinary home are fully adequate for proper flushing action and therefore, the single essential reason for the tank and mechanical assembly associated therewith is to provide a convenient time delay shut-off means for the water supply.
The disadvantages of the prior art residential toilet installation are primarily threefold. First, the cost associated with the tank and the various floats, mechanical linkages, etc., is substantial, both in initial purchase cost and in cost of installation. Secondly, such installations require a reasonable amount of maintenance, such as required periodic replacement of valve seats, floats, etc. Thirdly, the tank itself is physically fairly large and not easily packaged so as to be an attractive and aesthetically appealing article in the bathroom, thus making the toilet a generally dominating and unattractive feature of the room.
In commercial installation of the type which are manually flushed, it is common practice to eliminate the tank and to connect the remainder of the toilet directly to the water supply line through a mechanical time delay valve. These valves are adapted to open and to later automatically close in a manner actuated by and responsive to the water flow therethrough. Such valves are relatively complicated mechanical assemblies having an open duration which may not be adjustable, and requiring fabrication from brass and other expensive materials exhibiting suitable non-corrosive and durable characteristics. In other commercial installations where periodic flushing is achieved automatically, it is common to place a solenoid actuated valve in the water line and to operate the valve from an electromechanical timer, similar to the prior art sprinkler systems hereinabove described. Thus, it may be seen that in these prior art systems, there is considerable opportunity for cost and maintenance reduction, and particularly in residential installations for reducing the size and improving the appearance of the installations while simultaneously achieving the other heretofore-described desirable objects.